Chenoufi N, Loréal O, Drénou B, Cariou S, Hubert N, Leroyer P, Brissot P, Lescoat G
INSERM U 49, University Hospital Pontchaillou, Rennes, France.
J Hepatol. 1997 Mar;26(3):650-8. doi: 10.1016/s0168-8278(97)80432-1.
BACKGROUND/AIMS: Hepatocellular carcinoma develops frequently in the course of genetic hemochromatosis, and a role of iron overload in hepatic carcinogenesis is strongly suggested.
The aim of our study was to investigate the effect of iron exposure on DNA synthesis of adult rat hepatocytes maintained in primary culture stimulated or not by EGF/pyruvate and exposed to iron-citrate complex.
In EGF/pyruvate-stimulated cultures, the level of [3H] methyl thymidine incorporation was strongly increased as compared to unstimulated cultures. The addition of iron to stimulated cultures increased [3H] methyl thymidine incorporation. The mitotic index was also significantly higher at 72 h. However, the number of cells found in the cell layer was not significantly different from iron-citrate free culture. By flow cytometry, no difference in cell ploidy was found between iron-treated and untreated EGF/pyruvate-stimulated cultures. A significant increase in LDH leakage reflecting a toxic effect of iron was found in the cell medium 48 h after cell seeding. In addition, [3H] methyl thymidine incorporation in the presence of hydroxyurea was increased in iron-treated compared to untreated cultures.
Our results show that DNA synthesis is increased in the presence of iron in rat hepatocyte cultures stimulated by EGF/pyruvate, and they suggest that DNA synthesis is likely to be related both to cell proliferation and to DNA repair. These observations may allow better understanding of the role of iron overload in the development of hepatocellular carcinoma.
背景/目的：肝细胞癌常在遗传性血色素沉着症病程中发生，强烈提示铁过载在肝癌发生中起作用。
我们研究的目的是调查铁暴露对原代培养的成年大鼠肝细胞DNA合成的影响，这些肝细胞在有无表皮生长因子（EGF）/丙酮酸刺激下，并暴露于柠檬酸铁复合物。
在EGF/丙酮酸刺激的培养物中，与未刺激的培养物相比，[3H]甲基胸苷掺入水平显著增加。向刺激的培养物中添加铁增加了[3H]甲基胸苷掺入。有丝分裂指数在72小时时也显著更高。然而，细胞层中的细胞数量与无柠檬酸铁培养物相比无显著差异。通过流式细胞术，在经铁处理和未处理的EGF/丙酮酸刺激的培养物之间未发现细胞倍性差异。在细胞接种48小时后，细胞培养基中反映铁毒性作用的乳酸脱氢酶（LDH）泄漏显著增加。此外，与未处理的培养物相比，经铁处理的培养物在羟基脲存在下的[3H]甲基胸苷掺入增加。
我们的结果表明，在EGF/丙酮酸刺激的大鼠肝细胞培养物中，铁的存在会增加DNA合成，并且提示DNA合成可能与细胞增殖和DNA修复都有关。这些观察结果可能有助于更好地理解铁过载在肝细胞癌发生中的作用。
